U.S. Pat. No. 4,454,615, to Whitney, which is assigned to the assignee of the present invention, discloses an overlay comprising an air cell. This overlay does not provide means for inclining the upper surface.
U.S. patent application Ser. No. 08/943,286, filed Oct. 3, 1996 now abandoned, which is assigned to the assignee of the present invention and which is incorporated herein by reference, discloses a mattress having air cell means and foam crib members assembled within a mattress cover. An externally disposed pump routes air through air lines directly to air cell means. The air cell means includes individually inflatable side-by-side air cells and individually inflatable side-by-side bladders underneath the air cells respectively. The air cells and bladders are heat welded together to allow the upper surface of the mattress to be inclined to one side. This mattress satisfies its intended purpose but it is expensive. It is therefore desired to provide an inexpensive, disposable, and replaceable overlay with air cells. The desired overlay allows the upper surface to incline and eliminates the necessity of cleaning and sanitizing after each patient use.
U.S. Pat. Nos. 5,249,319 and 5,325,551 disclose mattresses having air cells or plenums, crib structures, and blowers or air pumps all within a mattress cover. These assemblies also do not allow for disposability of the components as contemplated by the present invention.
It is an object of the present invention to be able to incline the upper surface thereof to one side for patient management.